Composite materials comprised of alloy and ceramic materials are known and are ideally suited for use in products requiring high temperature tolerance and wear resistance, which is typically associated with ceramics, and toughness, which is typically associated with metals or alloys. As such, the composite materials provide desirable wear, thermal, and hardness characteristics to products made from such materials. When products are made from only a ceramic or only an alloy the products often lack the necessary combination of characteristics required for certain uses. For instance, steel alloys have been used to form a variety of products, but the use of steel has been undesired because it often does not impart sufficient thermal resistance for use in certain types of products. Ceramics impart high thermal resistance, but are generally not strong enough and do not have a high fracture toughness. For these reasons composites are desirable because they combine the desirable characteristics of both alloys and ceramics.
Engine components, such as valve guides and mechanical seals for example, are subject to high temperature environments and are also subject to harsh conditions which test the strength and wear resistance of the components. For these types of components it is desired to use a composite material comprised of an alloy or metal and a ceramic because of the desired combined characteristics. Specifically, the mentioned engine components require high temperature tolerance and increased hardness and wear resistance characteristics, so that the components require the characteristics associated with the alloys and the ceramics.
The composite compositions, however, have typically not been used to form the above-mentioned types of components and devices because the process for forming products from such composite compositions has generally been too expensive. Hot isostatic pressing is an example of a method that has been previously used to produce ceramic alloy composite compositions. Unfortunately, hot isostatic pressing is currently an expensive process to perform and the composite compositions have to be produced and then machined into a finished product. Machining composite compositions into a finished component or product is generally expensive. For these reasons, it is desired to have a process, other than hot isostatic pressing, for producing composite compositions. It is further desired to have a process for forming composite compositions which is presently not economically prohibitive and which is suited for use in the production of various engine components. Additionally, it is desired to have a process for forming composite compositions which does not require extensive machining of products made from the composite materials, but which instead allows for the production of the component during formation of the composite composition. In other words, it is desired to form a ceramic of the desired component shape and then form the composite composition.